<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        h1{
            color: var(--merchantColor);
        }
    </style>
</head>
<body>
    <!-- 自定义参数参数值 -->
    <h1 style="--merchantColor: skyblue">Hello World</h1>
</body>
</html>
<script>    
</script>